(1B) Click Browse and select the AASPI-format file (*.H) that you want to display. After you browse the file, the Colorbar file name (1C), plot title

Transcription

1 QC PLOTTING OF AASPI-FORMAT DATA AND ATTRIBUTES Program aaspi_plot The AASPI QC Plotting tab To further quality control the conversion process, you will wish to plot your data before computing seismic attributes. You will also wish to plot your attributes before converting them to SEGY format prior to importation into your interpretation workstation software. In the aaspi_util GUI (1A) Click the tab labeled AASPI QC Plotting. The panel below appears. 1A 1D 1B 1C 1E 1F 1G 1H 1J 1I (1B) Click Browse and select the AASPI-format file (*.H) that you want to display. After you browse the file, the Colorbar file name (1C), plot title Attribute-Assisted Seismic Processing and Interpretation Page 1

2 (1D), and all axes parameters (1E) are automatically loaded. You can change all those fields to your need. By default, desired axes 1, 2, 3 are time, cdp, and line, respectively (1F). This default selection correspond to inline display type, where each panel is an inline view, with cdp as the horizontal axis and time as the vertical axis. To change the display type to cross-line view, make sure the desired axis 3 is CDP no. Similarly, to change the display type to time-slice view, make sure the desired axis 3 is Time. Note that each time you change the display type, the increment value for the 3 rd axis would be set to be 10x the original increment. For example, if you select time as the 3 rd axis, and your sample interval is 0.004s, then the time increment is automatically set at 0.04s. This is recommended because it would help increase the display loading speed by cropping the data to the new increment of the 3 rd axis and generate a smaller volume to be displayed. By default, auto-scaling is active (1G). This means the program will use statistical percentage clip to scale the data to appropriate color level. The default percentage histogram clip is 98 (1H), meaning only values between 1% and 99% of the data statistical distribution will be taken into the scaling process. Data falls below 1% or above 99% of the distribution would be clipped. Anything in between 1% and 99% distribution will be scaled in between. This is useful when you are comparing seismic amplitude data with different processing flows or different surveys that have different range of values. Click on (1G) would switch between auto-scaling and fixed-scaling modes. In fixed-scale mode, you need to define a minimum and maximum values (1H). These values are automatically loaded when you browse the input file and you can always change them to your need. Data falls below the minimum or above the maximum would be clipped. The display color would be scaled linearly from minimum value to maximum value. If the browsed data have both positive and negative values (e.g. seismic amplitude, curvatures ), specify All-positive to n (1I). Otherwise (e.g. coherence, dip magnitude ) select y. After all the parameters are set, click Execute (1J). The following figure generated by the program aaspi_plot appears: Attribute-Assisted Seismic Processing and Interpretation Page 2

3 2B 2A Attribute-Assisted Seismic Processing and Interpretation Page 3

4 Basic interaction with aaspi_plot GUI By default, the display panel will scale the vertical axis using a 3000ft/s conversion velocity (for inline and cross-line display type) or using the correct 1 inline : 1 cross-line (for time-slice display type). Click on 2A to switch to the window-size fitting mode. Click again to switch back to scaling using velocity conversion mode. You can change the replacement velocity and hit Apply to rescale the plot to your need. Click on 2B to turn on/off bilinear interpolation of the image. Interpolation makes the image look smoother. However, in some cases, it should be turned off to prevent interpolation artifacts, such as azimuthal wrap-around. Click on the double right arrow button (3A) to move to next panel (e.g. move to the next inline in inline display type). Similarly, click on the double left arrow button to move to the previous panel. The single right arrow is used to play forward the panel as a movie. To play the movie in a loop, check-mark the loop option (3B). Left arrow button is for playing backward. Square button is to stop the movie. This is useful to animate through different panels in order to see the change of a geologic feature (such as a fault or a bedding surface). The right most and left most button is used to quickly switch to the last or the first panel view. To view the coordinate and value of a data point, left click on the data point of interest (3C). The coordinate and value of the data point is displayed in the bottom status bar (3D). Note that the value are the number inside the parentheses. Attribute-Assisted Seismic Processing and Interpretation Page 4

5 3B 3A 3C 3D To go to a specific panel of interest, click (4A) File, Goto to open the Goto panel. In this panel, you can either (4B) move the slider, or alternatively, type in the panel number on the right (4C) and click (4D) Apply. The label of the panel will change accordingly (4E). 4A 4B 4C 4E 4D Settings AASPI Plot GUI allows you to manually change plotting parameters after a data is displayed. Click on (5A) File Settings to open the settings dialog. Attribute-Assisted Seismic Processing and Interpretation Page 5

6 5C 5D 5A 5E 5F 5B 5G In the general tab (5B), you can specify whether to show color bar, transpose image, reverse axes, and reverse color bar. If you are comparing two data of the same type but with different ranges of values (for example, seismic amplitude reprocessed in different workflow), it is better to turn off the color bar to maintain the exact size of the main plot area. In the Title/Labels tab (5C), you can change the title of the plot, as well as the axes labels and color bar label. The data ranges tab (5D) is probably the most important one that you will regularly use. This tab allow you to change from statistical scaling mode using histogram percentage distribution to fixed scale mode using minimum and maximum values(5e). These modes are mutually exclusive, so you can only use one of them at a time. Statistical scaling parameters are in box (5F), while fixed scaling parameters are in box (5G). Note that if Symmetric about bias is activated and Data bias is 0, then it would correspond to All-positive set to n in the QC plotting tab of aaspi_util, meaning your data has both positive and negative values (e.g. amplitude, curvatures ) and you want to set zero value as the middle color of the color bar. If your data values are all positive, uncheck Symmetric about bias. Changing Color Bar The color bar can be browsed in the QC Plotting tab. However, if you want to change the color bar after the data is displayed, go to (6A) File Change Color Table. The color bar dialog will pop up, allow you to change Attribute-Assisted Seismic Processing and Interpretation Page 6

7 the color bar to your need (6B) and to reverse it if needed. Then click (6C) Apply (or OK) to see the change. 6A 6B 6C Exporting Graphics Files Program aaspi_plot allows you to export PNG (Linux only), JPEG (Linux only), GIF, and BMP format graphics files for use in reports and publications. This may be particularly useful in exporting images that appear better when using 24-bit color tables. There are two options to export the image. 1. Save the entire image: click (7A) File Save Image. This will save the entire image, including color bar, titles, and axes labels to an image file (7B). 2. Save only the plotting area: click (7C) File Save. This will only save the plotting area to an image file (7D). Give the file a name (7E), choose export format (7F), and click OK (7G). Attribute-Assisted Seismic Processing and Interpretation Page 7

8 7A 7C 7E 7F 7G 7B 7D Co-rendering two attributes To co-render two attributes, go to Display Tools aaspi_corender (8A). Currently we support single display (no blending) and alpha blending with two layers (8B). We planned to implement RGB and HLS blending methods soon. In the tab book, specify input file, input color bar, as well as statistical or normal max-min ranging parameters for the base layer (8C) as well as the second layer (8D). In layer 2 tab, choose appropriate opacity curve for blending (8E). There are 5 choices of opacity curves: - Positive linear: low values are transparent, while high values are opaque Attribute-Assisted Seismic Processing and Interpretation Page 8

9 - Negative linear: low values are opaqe, while high values are transparent - > : near-zero values are opaque, while positive and negative values are transparent - < : near-zero values are transparent, while positive and negative values are opaque - Custom: use the embedded alpha channel in the color bar file (usually Petrel *.alut file). If an.alut file is selected for the color bar, this choice is automatically selected. Attribute-Assisted Seismic Processing and Interpretation Page 9

10 8A 8B 8C 8D 8G 8F 8E 8H Attribute-Assisted Seismic Processing and Interpretation Page 10

11 In this case, we are plotting curvature as the 2 nd layer, we want to use < opacity curve type to enhance the high positive and low negative values of curvature. Notice that we also created a binary blue-red color bar, which has all red for positive values and all blue for negative value, for this blending purpose (8F). After the two layers parameters are set up, specify common parameters for plotting (8G). This is similar to the QC plot tab in aaspi_util. Finally, hit Execute (8H). The figure below shows the co-rendered result of coherence (specifically energy-ratio similarity) and most positive curvature (k 1 ) on a time-slice. Attribute-Assisted Seismic Processing and Interpretation Page 11

12 If somehow you want to change co-rendering parameters for the two attributes after they are plotted, in aaspi_plot, click File Open for blending (9A). This window show almost exactly the same settings you applied to the two layers in aaspi_corender, including blending type, input file, color bar, scaling parameters, and opacity curve type (9B). Note that the input files are not the actual attributes, but rather a cropped / sliced / transposed versions of them. This is a good practice for plotting since it allows us to view the data in time slice and X-line mode, as well as increasing the panel increment so we can go through the data quicker. Change the parameters to your need, and click Apply/OK (9C) 9A 9B 9C Attribute-Assisted Seismic Processing and Interpretation Page 12

13 Looking under the hood: GUIs, parameter files, shell scripts, and application programs A few users and the system administrators may wish to know how we have put this software together. The components were discussed in reviewing our migration plans to support Windows in Section 1. The AASPI software is driven by a collection of graphical user interfaces (GUIs) written in C++ and using the Fox toolkit. These GUI read default and user-supplied parameters to generate a parameter file, which for the QC plotting program here is called aaspiviewer.parms: The GUI invokes a python script ${AASPIHOME}/pyscripts/ aaspi_aaspiviewer_poststack.py. The python script reads the parameters from the *.parms file, processes them, and then invokes application program aaspi_plot (written in C++ and also using the Fox toolkit). The bulk of our applications is written in Fortran95, run in parallel under MPI, and is not interactive. This fourlayer software architecture provides an interactive user interface, computationally efficient application codes, glued together with python scripts that provide multiplatform capabilities on Linux and Windows. If you were to inspect ${AASPIHOME}/pyscripts/ aaspi_aaspiviewer_poststack.py you would see that it reads the parameter values from the parameter file, such as those to determine whether we wish to plot time slices or vertical slices, a call to program crop that crops the data according to the input parameters, and program slice that generates time slices from the input cropped data sub-volume, prior to calling program aaspi_plot that actually plots the seismic data. Since we no longer will use pipes in order to move to Windows, we need to define temporary intermediate files. Unique temp_sliced and temp_cropped files are created by appending the time of execution to the file name. These temporary files are deleted when program aaspi_plot is closed. Occasionally, your system connection may be interrupted or a process may terminate abnormally. Nothing will be damaged if you remove any of the *.parms or temp* files in any of your directories. Attribute-Assisted Seismic Processing and Interpretation Page 13

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